pond is 17 wide by 23 feet long slopes from 4 ft to 6ft where one bottom drain sits 17 feet away from waterfall area.My waterfall is the whole 17 ft wide(indoor pond and wanted to keep it more quiet).my idea was to have the skimmer return by a couple of returns at bottom by chicken out cause way the dirt looked(liner pond no cement)>i was afraid of digging down for piping and watch a landslide.
my bottom drain is non aerated cause worried about humidity issue.my skimmer sit totally opposite of waterfall area.

so far i do see a little waste on bottom,nothing that concerns me but also not spotless.if i need a cleaning a little sinking food gets koi at bottom to keep moving along.

been thinking my koi are lazy and need more swimming so have tried putting an airstone on top of drain cover to see what would happen.i feel it may have helped clean the bottom but i saw more waste that was in water,not the floating kind for skimmer but waste being thrown and moving around from air on drain.

I have even thrown a submerisble pump in pond to see what would happen in i threw another pump and had TPRs. under watefall.feel that at about 5 ft from pump i really did not have any extra movement.so feel that 2 return pipes are not going to yield me much unless pond was about 5 feet wide and few feet deep to really create a current.
This is more of my first true koi pond(far from perfect) and have never had a pond where it had 2 bottom drains and aerated at each drain so really can not compare the 2 systems
I did my system for sake of $$$ and room ,one drain one pump one filter instead of 2 drains 2 pump and 2 filter.skimmer would be even in both cases.

BUT after seeing a few other ponds, i am thinking my next pond would be more figure 8 shaped with an aerated drain in the middle of each.course that would involve cement and being sprayed so $$$$$.I will stay being 90% happy with mine and do little experiments.

My observation has been that debris tends to accumulate at the pond wall under a waterfall, unless the waterfall is so strong as to create turbulence at the pond bottom. Having a sloped or saucered bottom reduces this accumulation. Having a circular flow in the pond also reduces the accumulation, with a strong current at or near the bottom being more effective. The combination of saucered bottom with air domes and circular flow usually eliminates the accumulation.

The debris you saw in the water indicates the currents were not sweeping settlement to the bottom drain, but away from it. I expect the airstone was too near the drain suction point. It would need to be centered over the drain and above it. This is difficult to accomplish without an airdome.

Since we are discussing keeping the pond bottom clean, has anyone tried installing pop-ups which spray 360 deg and as used in pool construction are set so the debree is pushed to surface skimmers or bottom drains? Seams like a good idea as long as they have enough pressure to pop through algae buildup.
Bob

Will it work? Yep. Are there disdvantages to this style of design? Yep again.

Lower pond volume.

Sketch is 2 dimensional. The Bakki retun shows 1 place for pond entry. what about the dead areas created either side of that entry point?

Unlike Tonio, I prefer in wall skimmers since no niche skimmers present additional hazards to the koi....obstruction and area for a koi to get caught within (which can be gaurded against on an in wall but not so for a no niche).

There is also not compensation for ever reducing currents at greater distances from the drain. Cyclonic currents coupled with an ever increasing slope to the bottom not only help to compensate for such, they (the ever increasing slope to the bottom) also add more water volume than a straight sloped bottom.

pond is 17 wide by 23 feet long slopes from 4 ft to 6ft where one bottom drain sits 17 feet away from waterfall area.My waterfall is the whole 17 ft wide(indoor pond and wanted to keep it more quiet).my idea was to have the skimmer return by a couple of returns at bottom by chicken out cause way the dirt looked(liner pond no cement)>i was afraid of digging down for piping and watch a landslide.
my bottom drain is non aerated cause worried about humidity issue.my skimmer sit totally opposite of waterfall area.

so far i do see a little waste on bottom,nothing that concerns me but also not spotless.if i need a cleaning a little sinking food gets koi at bottom to keep moving along.

been thinking my koi are lazy and need more swimming so have tried putting an airstone on top of drain cover to see what would happen.i feel it may have helped clean the bottom but i saw more waste that was in water,not the floating kind for skimmer but waste being thrown and moving around from air on drain.

I have even thrown a submerisble pump in pond to see what would happen in i threw another pump and had TPRs. under watefall.feel that at about 5 ft from pump i really did not have any extra movement.so feel that 2 return pipes are not going to yield me much unless pond was about 5 feet wide and few feet deep to really create a current.
This is more of my first true koi pond(far from perfect) and have never had a pond where it had 2 bottom drains and aerated at each drain so really can not compare the 2 systems
I did my system for sake of $$$ and room ,one drain one pump one filter instead of 2 drains 2 pump and 2 filter.skimmer would be even in both cases.

BUT after seeing a few other ponds, i am thinking my next pond would be more figure 8 shaped with an aerated drain in the middle of each.course that would involve cement and being sprayed so $$$$$.I will stay being 90% happy with mine and do little experiments.

Thanks for the input Mike. I am also concerned about Ryan's design because the water flowing through the bakki shower will be returned via most likely two 4" pipes that will enter the pond at the bottom of the shallow end (will post a design as soon as I have a chance). If the two 4" pipes are spread evenly across the 10' width, then that's approx 3.3' apart. This may be too much of a spread to sweep debris on the shallow end. I believe that this is why most of the river systems that I have seen are very narrow and long (hence "river"). Will have to discuss with Ryan on this one.

Since we are discussing keeping the pond bottom clean, has anyone tried installing pop-ups which spray 360 deg and as used in pool construction are set so the debree is pushed to surface skimmers or bottom drains? Seams like a good idea as long as they have enough pressure to pop through algae buildup.
Bob

Will it work? Yep. Are there disdvantages to this style of design? Yep again.

Lower pond volume.

Sketch is 2 dimensional. The Bakki retun shows 1 place for pond entry. what about the dead areas created either side of that entry point?There will actually be two 4" returns from the Bakki shower that will be spaced evenly along the 10' wide bottom. This equates to approx 3.3' apart. IMO, this is a little too wide for it to be able to sweep heavy solids that may settle at the corners and side of the shallow end. Most of the river systems that I have seen are narrow and long (contrary to the 1D x 2W x 4L standard/recommended dimensions).

Unlike Tonio, I prefer in wall skimmers since no niche skimmers present additional hazards to the koi....obstruction and area for a koi to get caught within (which can be gaurded against on an in wall but not so for a no niche).I cannot agree with you more on this one.

There is also not compensation for ever reducing currents at greater distances from the drain. Cyclonic currents coupled with an ever increasing slope to the bottom not only help to compensate for such, they (the ever increasing slope to the bottom) also add more water volume than a straight sloped bottom.

Steve

Steve, first of all Merry Christmas to you and your family. Second, thank you for your input on this streamflow pond design (I was wondering when you were going to chime in). I know that you and Michael Anderson (MCA) and others are strong believers in the flat bottom pond with ABDs located at the center with TPRs and GPRs strategically placed for cyclonic currents for rapid solid removal, but please allow me and others to pick your guys' brains a little bit if we may. Please see next post.

I see nothing in the streambed approach that is not delivered in a deep "flat" bottom pond using airdomed bottom drains for each 5000-7500 gallons and/or each 100-150 square feet of floor combined with skimmers, TPRs..etc.

With traditional design, if fish want to be shallow, deep, or something in between...all they need to do is use their swim bladders and fins. In the streambed design if they want to be deep, they have to first be on the deep end.